Insights in to microstructural behaviour of self-cleaning Fly ash-blended portland pozzolana cement mortars containing nano TiO₂

¹ Research Scholar, Jawaharlal Nehru Technological University Anantapur, Ananthapuramu - 515002, Andhra Pradesh, India.
² Annamacharya Institute of Technology & Sciences, Kadapa, Affiliated to Jawaharlal Nehru Technological University Anantapur, Ananthapuramu -- 515002, Andhra Pradesh, India

^* Corresponding author: srichandanaloka@gmail.com

Abstract

The present study examined the influence of nano TiO2(NT) on the surface coating and intermixing behavior of fly ash-based Portland Pozzolana Cement (PPC) self-cleaning mortar discs at minimal dosages. Rietveld refinement and crystallographic analysis were performed to investigate the particle packing arrangements and structural modifications, and the morphological properties and hydration products were characterized by using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The experimental results suggest that the lattice parameters and volume of both the intermixed and surface- coated samples decreased, suggesting a dense crystal structure in comparison to those of the reference sample mortar. The hydration of both the intermixed and surface-coated samples increased, and a uniform densified microstructure formed, resulting in smaller portlandite (CH) crystal sizes and improved calcium silicate hydrate (CSH) gel distribution. Samples with surface coatings, particularly freshly cast and hardened coatings, demonstrate superior refinement quality and better alignment between the calculated and experimental XRD patterns.